Additive‐Free Nb2O5−TiO2 Hybrid Anode towards Low‐Cost and Safe Lithium‐Ion Batteries: A Green Electrode Material Produced in an Environmentally Friendly Process

AbstractThe development of additive‐free electrodes based on low‐cost and environmentally friendly materials is one of the major challenges for expanding sustainable and ecologically friendly energy storage. Most conventional electrode preparation processes are currently facing a problem: the addition of various additives/chemicals, particularly binder, carbon black and toxic N‐Methyl‐2‐pyrrolidone. These additives increase the production cost, decrease the energy and power density of the battery and are environmental hazards. Herein, a Nb2O5−TiO2 hybrid electrode for lithium‐ion batteries is fabricated by adopting the advanced radio frequency sputtering technique, which requires no supplementary support from additives/chemicals. The Nb2O5−TiO2 electrode reveals high capacity (gravimetric: 214 mAh g−1 at 50 mA g−1; areal: 0.0214 mAh cm−2 at 5 μA cm−2; volumetric: 1,813 mAh cm−3 at 5 μA cm−2), long‐term cyclic stability (gravimetric: 174 mAh g−1 at 0.4 A g−1; areal: 0.0174 mAh cm−2 at 40 μA cm−2; volumetric:1,474 mAh cm−3 at 40 μA cm−2 after 1000 cycles) and superior rate capability (gravimetric: 115 mAh g−1 at 6.0 A g−1; areal: 0.0115 mAh cm−2 at 6 mA cm−2; volumetric: 974 mAh cm−3 at 6 mA cm−2), which are better than other reported systems. Such a green chemistry strategy of fabricating additive‐free electrodes opens up new ways for the development of sustainable and robust energy storage technologies.